Abstract: In this paper, we study the structure and the thermal stability of gold atoms covered on the surface of carbon nanotubes by molecular dynamics simulations. It is shown that, diversiform stable structures can form on the surfaces of carbon nanotubes: when the density of gold atoms covered on the surfaces of carbon nanotubes is less than 15.91, gold atoms would form gold nanoparticles, when the density is between 15.91 and 104.98, gold atoms would form a series of cylindrical and helical shell structures, when the density is greater than 104.98, gold atoms would have the face centered cubic structure like the crystalline bulk gold. Further more, we have also studied the thermal stability of the helical shell nanowires with the carbon nanotubes' support. The results show that the melting point of the helical shell nanowires with the carbon nanotubes' support is lower than the gold nanowires formed in a free space, but higher than that of the gold nanoparticles.